Drum brake and brake shoe for one such brake

Abstract

A drum brake comprising a plate on which at least one shoe having a friction lining is mounted. A lever moves the shoe against a wheel drum in response to a braking command to effect a brake application. A resilient return spaces the shoe apart from the drum when braking ceases. The shoe is mounted to slide along an essentially radial axis between two guide walls secured to the plate The lever for applying the shoe bears against the inside wall of the shoe for exerting a substantially radial force.

Description

[0001] The invention relates to a drum brake including a plate on which at least one shoe provided with a friction lining is mounted, application means for applying the shoe against a wheel drum in response to a braking command transmitted by a wheel cylinder, and resilient return means for spacing the shoe apart from the drum when braking ceases. BACKGROUND OF THE INVENTION [0002] Conventional-type drum brakes include an abutment that is fixed or that moves relative to the plate to which a first end of the shoe is fixed, which first end is opposite from a second end in contact with the wheel cylinder, the wheel cylinder transmitting the braking command directly to the shoe which is mounted to pivot relative to the plate at its end fixed to the abutment. [0003] Drum brakes offer several advantages over disk brakes. For the same application force, the braking torque is generally larger in a drum brake than in a disk brake. The “handbrake” function is easier to install on a drum brake...

AI Technical Summary

Benefits of technology

The invention provides a drum brake with a simplified shoe replacement process and improved braking torque stability. The shoe is mounted to slide along a radial axis between guide walls and is applied against the inside wall of the shoe using an application lever. The brake includes a plate and shoes that are mounted on the plate and can be easily replaced. The brake also includes resilient return means for spacing the shoes apart from the drum when braking ceases. The invention also provides a shoe with a friction lining bonded to a rigid support and a lever for applying the shoe against the wheel drum. The brake can be organized so that the axis of the reaction force is offset relative to the axis of the inlet force. The lever has a flat shape and a hump that comes to bear against the inside wall of the shoe. The brake also includes a plate and shoes that are mounted on the plate and can be easily replaced. The brake includes resilient return means for spacing the shoes apart from the drum when braking ceases. The invention also provides a shoe with a friction lining bonded to a rigid support and a lever for applying the shoe against the wheel drum.

Problems solved by technology

However, replacing a drum brake shoe when its friction lining is worn requires a relatively long disassembly and reassembly operation to be performed.

Because of the way forces exerted in the drum brake are distributed during braking, the shoe is subjected to a roll-up phenomenon that can reduce the stability of the braking and therefore the stability of the vehicle.

The fact that the braking force and the reaction force are applied at the same point tends to give rise to shoe roll-up.

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